The Sandwich Tern Thalasseus sandvicensis occurs throughout the coastal regions of southern Africa but tends to favour major bays, coastal lagoons and suitable river mouths. There is a great disparity in counts at any one locality from year to year. Overall austral summer population was estimated at 10 000-15 000 in a good year and probably <10 000 in a poor year. Banding recoveries indicated origins in western Europe (354 birds recovered) and, rarely, from the Black or Caspian seas (two birds recovered). Movements occur continuously within the subregion of southern Africa throughout summer, as indicated by varying counts and two within-season recoveries. The oldest bird recovered was in its 28th year. Recoveries of birds in their first year (23%) varied as to source: the highest recovery rates were for birds originating in Germany and Denmark, while the lowest rates were for birds originating in Britain (England/Scotland) and the Netherlands. The recovery rate increased from the second year of life. Most recoveries were of dead birds, with the majority of records indicating "found dead" with no further details. Band recoveries have varied in frequency over the last 80 years along different sections of coastline. Arrivals occur along the west coast from September to November for adults, but may continue through to March for young birds, with the last presumed breeding birds departing by early April. Small numbers of nonbreeders, up to 5 years old, may overwinter on the west coast, but very few were found at this time on south and east coasts. Migration is nocturnal or diurnal, inshore and normally at altitudes varying from 100 m to 300 m but may be much higher. Mass gains vary from about 25% to 45%, indicating short- to medium-hop migration. Within southern Africa there are a series of recognised staging localities that are used mainly for resting with limited, if any, feeding observed at most of them. Keywords: Sandwich Tern, Thalasseus sandvicensis, southern Africa, counts, distribution, band recoveries, roost sites, migrations.